Why We Lie: The Science Behind Our Deceptive Ways

In the fall of 1989 Princeton University welcomed into its freshman class a young man named Alexi Santana, whose life story the admissions committee had found extraordinarily compelling.

He had barely received any formal schooling. He had spent his adolescence almost entirely on his own, living outdoors in Utah, where he’d herded cattle, raised sheep, and read philosophy. Running in the Mojave Desert, he had trained himself to be a distance runner.

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Most children can’t resist peeking, Lee and his researchers have found by monitoring hidden cameras. The percentage of the children who peek and then lie about it depends on their age. Among two-year-old transgressors, only 30 percent are untruthful. Among three-year-olds, 50 percent lie. And by eight, about 80 percent claim they didn’t peek.

Kids also get better at lying as they get older. In guessing the toy that they secretly looked at, three- and four-year-olds typically blurt out the right answer, without realizing that this reveals their transgression and lying. At seven or eight, kids learn to mask their lying by deliberately giving a wrong answer or trying to make their answer seem like a reasoned guess.